ruby gem源更换国内源gems.ruby-china.org数据源
gem sources -l
gem sources --add https://gems.ruby-china.org/ --remove https://rubygems.org/
更新缓存
gem sources -u
gem sources -l
gem sources --add https://gems.ruby-china.org/ --remove https://rubygems.org/
更新缓存
gem sources -u